Epidemiology, Biostatistics and Mathematical Modelling, Scientific Services, Unit 33, Federal Institute for Risk Assessment (Bundesinstitut für Riskobewertung BfR), Diedersdorfer Weg 1, D-12277 Berlin, Germany.
Int J Food Microbiol. 2011 Mar 15;146(1):99-104. doi: 10.1016/j.ijfoodmicro.2011.01.041. Epub 2011 Mar 2.
Shiga toxin-producing strains of Escherichia coli (STEC) cause diarrhoea and haemorrhagic colitis in humans. Most human infections are attributed to consumption of STEC contaminated foodstuff. Food producing animals constitute important reservoirs of STEC and serve as source of food contamination. In this study, we have analyzed 593 foodborne STEC strains for their serotypes and for nine virulence genes (stx1, stx1c, stx1d, stx2, stx2b, stx2e, stx2g, E-hly and eae). The 593 STEC strains grouped into 215 serotypes, and 123 serotypes (57.2%) were represented each by only one STEC isolate. Fifteen serotypes (7.0%) were attributed to 198 (33.3%) of the 593 STEC strains. The foodborne STEC were grouped into different categories in relation to the species of the food producing animal (cattle, pigs, sheep, goats, red deer, wild-boar and hare). Univariate and multivariate statistical analyses revealed significant similarities between the animal origin of the food and the virulence markers of foodborne STEC. Significant associations (p<0.001) were found for stx1 and for stx2 with bovine meat and milk products. The stx2e gene was significantly (p<0.001) associated with STEC from pork and wild boar meat. Stx1c and stx2b genes were significantly (p<0.001) more frequent in STEC from deer meat, as well as from meat and milk products derived from sheep and goats. Using logistic regression models we detected significant (p<0.01) combinations between stx1, stx2 and E-hly genes and STEC from bovine meat. The combination of stx1c and stx2b genes was significant (p<0.001) for STEC derived from red deer, sheep and goat products. The properties of foodborne STEC were compared with published data on faecal STEC from food producing animals. Virulence profiles and serotypes of STEC from food showed remarkable similarities to those of faecal STEC that were from the same animal species. The findings from our study clearly indicate that the food producing animals represent the most important source for the entry of STEC in the food chain. Sound hygiene measures implemented at critical stages of food production (milking, slaughtering, and evisceration) should be most effective in reducing the frequency of STEC contamination of food derived from domestic and wildlife animals.
产志贺毒素大肠杆菌（STEC）菌株可引起人类腹泻和出血性结肠炎。大多数人类感染归因于食用被 STEC 污染的食物。食品生产动物是 STEC 的重要储存库，也是食物污染的来源。在这项研究中，我们分析了 593 株食源性病原体 STEC 的血清型和 9 种毒力基因（stx1、stx1c、stx1d、stx2、stx2b、stx2e、stx2g、E-hly 和 eae）。593 株 STEC 分为 215 个血清型，其中 123 个血清型（57.2%）仅由一株 STEC 分离株代表。15 个血清型（7.0%）归因于 593 株 STEC 中的 198 株（33.3%）。食源性病原体 STEC 根据食品生产动物（牛、猪、羊、山羊、马鹿、野猪和野兔）的种类分为不同类别。单变量和多变量统计分析显示，食品动物的来源与食源性病原体 STEC 的毒力标记物之间存在显著相似性。stx1 和 stx2 与牛肉类和奶制品显著相关（p<0.001）。stx2e 基因与猪肉和野猪肉中的 STEC 显著相关（p<0.001）。stx1c 和 stx2b 基因在鹿肉以及来自绵羊和山羊的肉类和奶制品中更为频繁，这与 STEC 显著相关（p<0.001）。使用逻辑回归模型，我们检测到与牛肉类 STEC 显著相关的 stx1、stx2 和 E-hly 基因的组合（p<0.01）。stx1c 和 stx2b 基因的组合与来自马鹿、绵羊和山羊产品的 STEC 显著相关（p<0.001）。食源性病原体 STEC 的特性与来自食品生产动物的粪便 STEC 的已发表数据进行了比较。食源性病原体 STEC 的毒力谱和血清型与来自同一动物物种的粪便 STEC 非常相似。本研究的结果清楚地表明，食品生产动物是 STEC 进入食物链的最重要来源。在食品生产的关键阶段（挤奶、屠宰和去内脏）实施合理的卫生措施，应能最有效地减少源自家养和野生动物的食品中 STEC 的污染频率。
